RAS2 of Saccharomyces cerevisiae is required for gluconeogenic growth and proper response to nutrient limitation

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Updated: Oct 23, 2026

Assay for Adhesion and Agar Invasion in S. cerevisiae
04:36

Assay for Adhesion and Agar Invasion in S. cerevisiae

Published on: November 7, 2006

K Tatchell, L C Robinson, M Breitenbach

    Proceedings of the National Academy of Sciences of the United States of America
    |June 1, 1985
    PubMed

    Insights

    Disrupting Saccharomyces cerevisiae RAS2 gene impairs growth on non-fermentable carbon sources and causes carbohydrate over-accumulation. Suppressors indicate RAS genes are vital for nutrient limitation response.

    Area of Science:

    • Molecular Biology
    • Yeast Genetics
    • Cellular Metabolism

    Background:

    • Saccharomyces cerevisiae possesses two RAS genes, RAS1 and RAS2, homologous to ras oncogenes.
    • These RAS genes are essential for yeast viability, as double-gene disruptions prevent growth.
    • RAS gene function in nutrient response pathways is not fully understood.

    Purpose of the Study:

    • To investigate the function of RAS genes in Saccharomyces cerevisiae.
    • To characterize the phenotypes associated with RAS2 gene disruption.
    • To identify genetic suppressors of RAS2 mutations to elucidate RAS pathway components.

    Main Methods:

    • Gene disruption of RAS2 in Saccharomyces cerevisiae.
    • Phenotypic analysis of RAS2 mutants on various carbon sources.
    • Isolation and characterization of extragenic suppressors.
    • Complementation analysis of suppressor mutations.

    Main Results:

    • RAS2 disruption leads to impaired growth on non-fermentable carbon sources.
    • RAS2 mutants exhibit hyperaccumulation of glycogen and trehalose.
    • Diploid RAS2 homozygous mutants sporulate on rich media.
    • Extragenic suppressors were identified, with some bypassing the essentiality of RAS genes.

    Conclusions:

    • The RAS2 gene product is crucial for efficient utilization of non-fermentable carbon sources.
    • RAS genes play a significant role in regulating carbohydrate storage.
    • RAS pathway is implicated in the cellular response to nutrient limitation.
    • Genetic interactions suggest novel components interacting with the RAS pathway.

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